I don't think that was the reason. She had a partial hysterectomy at age 36. She could have had children before that but as a lifelong slut she would not have been sure who the father was, so she probably aborted any earlier pregnancies. She always had an 'open' marriage with her husband.
That “open marriage” reminds me that I was always curious about her siblings. They seemed to stay out of the way. Never heard much about them. The few group photos I’ve seen seem to show, maybe, two girls that look like they could be sisters. The rest look more like they belong to the mailman. Couldn’t really blame Parton for splitting as soon as she graduated from high school. And bless her Mom for keeping the herd together but with no money how did she acquire all those musical instruments?
I heard that she 'was faithful' to her husband for 50 some years... 🤔